[1. Coretta Standard Method No. 20: Determination of alkaloids in manufactured tobacco; Coresta Inf.Bull. 1969-2, 25-27.]Search in Google Scholar
[2. Dirks, B., and F. Scheffer: Z. Pflanzenem., Düngung und Bodenk. 1933, 428.]Search in Google Scholar
[3. Fuqua, B. D., J. L. Sims, J. E. Leggett, J. F. Berner and W. 0. Atkinson: Nitrate and chloride fertilization effects on yield and chemical composition of Burley tobacco leaves and smoke; Can. J. Plant Sci. 56 (1976) 893-899.]Search in Google Scholar
[4. Lulov, K. B.: Agrotechnics of Nevrokop 261 tobacco variety in Nevrokop area; Nauchni Trud., Plovdiv, 1974-4,91-106.]Search in Google Scholar
[5. McCants, C. B., and W. G. Woltz: Growth and mineral nutrition of tobacco; Advances in Agronomy 19 (1967) 211-265.10.1016/S0065-2113(08)60736-1]Search in Google Scholar
[6. Olsen, S. R., C. V. Cole, F. S. Watanabe and L. A. Dean: Estimation of available phosphorus in soils by extraction with sodium bicarbonate; U.S. Dept. Agr. Circ. 939, 1954.]Search in Google Scholar
[7. Shoumarski, N.: Fertilizer application to Oriental tobacco; Bulg. Tyutyum 18 (1973) 25-29.]Search in Google Scholar
[8. Tariman, C., and Y. M. Majumder: Effects of nitrogenous and potassium fertilizers on the yield and quality of Samsun Maden tobacco variety (Nicotiana tabacum); Bangladesh J. Sci. (Ind. Res.) 12 (1977) 81-90.]Search in Google Scholar
[9. Todorovski, P. J.: Influence of increasing rates of nitrogen, phosphate and potassium fenilizers on the yield and quality of Otlja type tobacco; 5th lnt. Tob. Sci. Congr. (Proc.), Hamburg, 1970, 176.]Search in Google Scholar
[10. Zulpiev, T., B. Atyshev and A. Kurbanaliev: Botanical variety, fertilizer, tobacco yield and quality; Tabak, USSR, 1971-4, 11-13.]Search in Google Scholar